"The sea continues to be a graveyard," charity Médecins Sans Frontières (MSF) said in a tweet.

According to the United Nations' High Commissioner for Refugees (UNHCR), more than 30,200 migrants and refugees have attempted to reach Europe by crossing the Mediterranean Sea in 2017 alone. At least 905 people have died or gone missing in the same time.

Darrin Zammit Lupi, a Reuters photographer who was present during Friday's rescue operations, said: "In 19 years of covering the migration story, I have never experienced anything like today."

The rescues come at a time when relationships between aid organisations and Frontex, the European Border and Coast Guard Agency, are fraught.

Frontex has accused groups such as MSF of acting "like taxis" for migrants and colluding with Libyan smugglers. Aid groups deny the claims, stating that their work is the difference between life and death.

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dinghy rescue

In a tweet directed at Forex, European Commission President Jean-Claude Juncker and European Council President Donald Tusk, MSF said: "How many people would have crossed if we weren't there today, Frontex? Probably the same.

"How many would have died? Probably, many more."

A number of journalists have also come forward to defend the work of NGOs in the Mediterranean, amid the accusations.